Contingency management (CM) interventions are highly efficacious in enhancing retention in treatment and reducing drug use. Growing evidence suggests these treatments can be adapted to alter a variety of behaviors, including health-related physical activities. Physical activity has beneficial effects on reducing depression and improving health. We have pilot data suggesting that drug abusing patients who engage in exercise to earn reinforcement have improved drug abuse outcomes relative to those who do not engage in exercise during CM treatments. In this Stage 1 therapy development project, we plan to develop, formalize, and derive effect size estimates of a CM therapy that focuses on improving health, especially as related to increasing low intensity physical activities, such as walking, resistance training, and stretching. The Healthy Activities for Prize Incentives (HAPI) intervention will be targeted toward and tested within HIV-positive substance abusers who attend HIV drop-in centers. After initial therapy development in a Stage 1a pilot project with 9 patients, the therapy manuals and materials will be adapted and refined. In a Stage Ib controlled trial, we will recruit and randomize 50 substance abusing HIV-positive patients to (a) HAPI plus 12-step facilitation therapy or (b) CM for abstinence plus 12-step facilitation therapy. Each intervention will consist of one weekly individual therapy session for 16 weeks. All participants will provide urine and breathe specimens twice weekly that will be tested for opioids, stimulants, marijuana and alcohol. Patients in both conditions will earn the chance to win prizes for submitting drug-negative specimens, and those randomized to the HAPI condition will also earn the chance to win prizes for engaging in healthy activities. Physical activity levels, drug use, psychological symptoms, and subjective and objective indicators of health (body mass index, waist circumference, blood pressure, viral load) will be measured pre-treatment and at months 2 and 4 (post- treatment), as well as at a 7-month (3 months after treatment) follow-up evaluation. Compared to that receiving 12-step facilitation with CM for abstinence, we expect that those in the HAPI condition will participate in more physical activities, decrease drug use to a greater extent, evidence reduced depression, and show trends toward improvements in health indices. If effect sizes in at least the small to medium range are noted across all domains, we will consider the therapy appropriate for further evaluation in a Stage 2 therapy development study.